Yarn spinning apparatus

ABSTRACT

A self-twist spinning machine comprising a drafting mechanism and an oscillating roller twisting mechanism, positioned in front of the drafting mechanism, wherein there is provided, in the region between the twisting rollers and the drafting mechanism, a plurality of vanes which are laterally spaced from one another and which extend in the direction of travel of the strands and serve to define separate paths for the strands through the said region.

United States Patent 1191 Hedaway July 3, 1973 1 YARN SPINNING APPARATUS 3,488,936 1/1970 Wyatt s7/77.4 2,294,771 9/1942 Campbell 57/774 Inventor: Bernard Milton Hedaway,

' Victoria, Australia Assignee: Commonwealth Scientific and Industrial Research Organization, Campbell, Australia Filed: Feb. 9, 1971 Appl. No.: 114,015

References Cited UNITED STATES PATENTS 3,377,792 4/1968 Walls et al. 57/77.4 X

Primary Examiner.lohn Petrakes Attorney-Sughrue, Rothwell, Mion, Zinn & Macpeak [5 7] ABSTRACT A self-twist spinning machine comprising a drafting mechanism and an oscillating roller twisting mechanism, positioned in front of the drafting mechanism, wherein there is provided, in the region between the twisting rollers and the drafting mechanism, a plurality of vanes which are laterally spaced from one another and which extend in the direction of travel of the strands and serve to define separate paths for the strands through the said region.

6 Claims, 3 Drawing Figures YARN SPINNING APPARATUS BACKGROUND OF THE INVENTION 1. Field of Invention This invention relates to apparatus for the production of yarn and particularly to apparatus of the type disclosed in the specification of Australian Pat. No. 288,664.

2. Description of Prior Art In the aforesaid apparatus strands, generally in the form of staple fiber rovings, are attentuated in a drafting mechanism. The drafting mechanism may be a conventional type comprising rear drafting rollers, a drafting apron and front drafting rollers. After leaving the drafting mechanism the output sliver is then passed between a pair of rotating and transversely reciprocating twisting rollers where it is twisted in alternately opposite directions. A plurality of such rovings are passed in close proximity to one another, through the nip of the twisting rollers and are then converged in pairs to form yarn by the method disclosed in prior Australian Pat. No. 260,092. Apparatus of this type will hereinafter be called a self-twist spinning machine.

Due to the close proximity of the rovings to one another and to their rotation in alternately opposite directions upstream of the twisting rollers there is a tendency for fiber ends from one roving to be caught by an adjacent roving with a consequent entanglement of the rovings in the zone between the front drafting rollers and the twisting rollers. Entanglement of fibers sometimes also occurs in the zone between the front of the drafting apron and the front drafting rollers.

SUMMARY In order to overcome the aforementioned difficulties this invention provides apparatus of the type referred to above wherein there is provided, in the region between the twisting rollers and the drafting mechanism, a plurality of vanes which are laterally spaced from one another and which extend in the direction of travel of the strands and serve to define separate paths for the strands through the said region. Preferably, the vanes also extend rearwardly of the front drafting rollers and provide separate paths in the region between the front of the drafting apron and the front drafting rollers. The vanes are preferably mounted on a bar which extends transversely of the apparatus. Preferably, also the vanes each comprise a front portion which extends into the region in front of the front drafting rollers and a rear portion which extends in the region to the rear of them, the two portions being connected together by a portion of lesser height. The portion of lesser height is preferably formed by a radiused cut out portion and the front drafting rollers are provided with circumferential grooves to accommodate the vanes.

BRIEF DESCRIPTION OF THE DRAWINGS The invention may be better understood by reference to the accompanying drawings which show, by way of example, a presently preferred embodiment of the invention. In the drawings:

FIG. I is a schematic cross-sectional view through the apparatus showing the vanes in position,

FIG. 2 is a cross-sectional view on the line 2-2 in FIG. I and FIG. 3 is a cross-sectional view on the line 33 in FIG. I.

2 DESCRIPTION OF PREFERRED EMBODIMENT In the construction shown in FIG. 1 a yarn spinning apparatus of the general type described in the prior- Australian Pat. No. 288,664 is shown, comprising a pair of reciprocating and rotating twisting rollers 1, a pair of front drafting rollers 2, a pair of drafting aprons 3 and a pair of rear drafting rollers 4. In the particular construction in respect of which this invention is presently being applied, eight rovings 5 are processed simultaneously through the aprons and the rovings, after twisting by the twisting rollers l, are converged in pairs to form four yarns by the process described in Australian Patent No. 260,092. The strands are relatively close together as they pass through the drafting aprons being spaced apart of the order of only about 1 to 2 cm. In order to prevent wrapping of fiber ends, particularly in the region between the twisting rollers l and the front drafting rollers 2, vanes 6 are provided to keep the rovings separate from one another as they are fed through the drafting rollers and the twisting rollers until they are ultimately converged at the convergence guide 7 in front of the front drafting rollers. The vanes 6 are mounted on mounting bars 8 and 9 which extend transversely of the apparatus between the twisting rollers and the front drafting rollers and between the front drafting rollers and the drafting aprons respectively. The vanes 6 comprise a front portion 11 positioned above the bar 8 and a tail portion 12 positioned above the bar 9. The lower portions of the vanes being in fact embedded in the bars. There are nine such vanes across the length of the bars dividing them into eight sections each bounded by a vane. It will be seen that the front and rear sides of the bar 8 are radiused so that the bar can be fitted close to the nip of the twisting rollers and the front drafting rollers and it will be seen that the vane is likewise radiused at the front so that it can be fitted into the nip of the front drafting rollers. A part circular cut out portion 13 forms the mid-section of the vane and this cut out is shaped to fit within a groove 14 which is formed in the front drafting roller 2 opposite each vane. The rear bar 9 is provided with funnel shaped slots 16 through which the rovings 5 pass and are condensed to relatively narrow ribbons as they pass to the front drafting rollers. The bar 8 rests on wiper bar 17 which carries wiper blade 18 which wipes the lower front drafting roller 2. The bar 9 rests at each end on top of the upper surface of the earings (not shown) of the front drafting rollers.

In order to clear away fly from the apparatus a suction tube 19 is positioned with its inlet arranged below the front drafting rollers. The suction is arranged so that the air moves into the tube from under the drafting aprons from under the bottom twisting roller and past the bar 8 from the region of the nip of the twisting roller 1.

The vanes provided by this invention serve to define the path of the rovings through the front drafting rollers I and the twisting rollers and thereby prevent wrapping of fiber ends from one roving around an adjacent roving. Furthermore, the special construction of the vanes and the vane bar enables the vanes to be fitted neatly into position in the apparatus without increasing critical distances between the drafting rollers and the twisting rollers and between the drafting rollers and the drafting apron. Thus, the provision of vanes according to this invention provides a simple solution to a serious problem in the practical operation of the apparatus described in prior Australian Pat. No. 288,664. It will be appreciated of course that a number of variations and modifications may be made to the actual construction and shape of the vanes without departing from the spirit and scope of this invention which is to be understood as including every novel feature and combination of features herein disclosed.

I claim:

1. A self-twist spinning machine comprising a drafting mechanism which includes front and back pairs of drafting rollers, each pair forming a nip between them, and means to drive the respective pairs at differing speeds of rotation, an oscillating roller twisting mechanism positioned in front of the drafting mechanism and including a pair of twisting rollers forming a nip between them and twisting roller drive means to rotate the twisting rollers in mutually opposite directions and to reciprocate them longitudinally of their rotational axesin opposite phase, a plurality of flat vanes, and vane support means for mounting the vanes in substantially parallel relationship transversely to said rotational axes, said vanes extending substantially the entire distance between the nip of the front drafting roller and the nip of the twisting rollers to divide the region between those nips into separate channels, whereby, in use of the apparatus, a plurality of strands can be passed in substantially parallel relationship through the drafting mechanism to the nip between the twisting rollers with each strand disposed in a separate channel.

2. A self-twist spinning machine as claimed in claim 1, wherein the front edge of each vane in shaped to a pair of arcs following the circumference of the twisting rollers and meeting at a junction closely adjacent the nip between the twisting rollers.

3. A self-twist spinning machine as claimed in claim 1, wherein each vane comprises a front portion disposed between the front drafting rollers and the twisting rollers, a rear portion which extends rearwardly from the front drafting rollers and an intermediate connecting portion of lesser dimension than the front and rear portions in the plane of the vane perpendicular to the front to rear direction, and at least one of the front drafting rollers has circumferential grooves which receive the intermediate portions of the vanes, the rear portions of the vanes serving to divide the region immediate the rear of the front drafting rollers into separate channels. 1

4. A self-twist spinning machine as claimed in claim 3 wherein the intermediate part of each vane comprises a neck portion having two concavely curved arcuate segments defining the vane periphery with at least one of the arcuate segments following the circumference of one of the drafting rollers.

5. A self-twist spinning machine as claimed in claim 3, wherein the vane support means comprises a bar which extends transversely of the vanes between the front drafting rollers and the twisting rollers and to which the vanes are attached.

6. A self-twist spinning machine as claimed in claim 5, wherein the rear portions of the vanes are connected to a further transverse bar which is provided, between the vanes, with slots to guide and condense strands passing to the channels between the vanes. 

1. A self-twist spinning machine comprising a drafting mechanism which includes front and back pairs of drafting rollers, each pair forming a nip between them, and means to drive the respective pairs at differing speeds of rotation, an oscillating roller twisting mechanism positioned in front of the drafting mechanism and including a pair of twisting rollers forming a nip between them and twisting roller drive means to rotate the twisting rollers in mutually opposite directions and to reciprocate them longitudinally of their rotational axes in opposite phase, a plurality of flat vanes, and vane support means for mounting the vanes in substantially parallel relationship transversely to said rotational axes, said vanes extending substantially the entire distance between the nip of the front drafting roller and the nip of the twisting rollers to divide the region between those nips into separate channels, whereby, in use of the apparatus, a plurality of strands can be passed in substantially parallel relationship through the drafting mechanism to the nip between the twisting rollers with each strand disposed in a separate channel.
 2. A self-twist spinning machine as claimed in claim 1, wherein the front edge of each vane in shaped to a pair of arcs following the circumference of the twisting rollers and meeting at a junction closely adjacent the nip between the twisting rollers.
 3. A self-twist spinning machine as claimed in claim 1, wherein each vane comprises a front portion disposed between the front drafting rollers and the twisting rollers, a rear portion which extends rearwardly from the front drafting rollers and an intermediate connecting portion of lesser dimension than the front and rear portions in the plane of the vane perpendicular to the front to rear direction, and at least one of the front drafting rollers has circumferential grooves which receive the intermediate portions of the vanes, the rear portions of the vanes serving to divide the region immediate the rear of the front drafting rollers into separate channels.
 4. A self-twist spinning machine as claimed in claim 3 wherein the intermediate part of each vane comprises a neck portion having two concavely curved arcuate segments defining the vane periphery with at least one of the arcuate segments following the circumference of one of the drafting rollers.
 5. A self-twist spinning machine as claimed in claim 3, wherein the vane support means comprises a bar which extends transversely of the vanes between the front drafting rollers and the twisting rollers and to which the vanes are attached.
 6. A self-twist spinning machine as claimed in claim 5, wherein the rear portions of the vanes are connected to a further transverse bar which is provided, between the vanes, with slots to guide and condense strands passing to the channels between the vanes. 